var btn = document.getElementById('btn')
var hezi = document.getElementById('input')
var flag = 0
btn.onclick = function () {
    if (flag == 0) {
        hezi.style.display = 'block'
        hezi.value = '请搜索...'
        flag = 1
    } else {
        hezi.style.display = 'none'
        flag = 0
    }
}
hezi.onfocus = function () {
    if (hezi.value == '请搜索...') {
        hezi.value = ''
    }
}